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ATI Open vs. Closed AIGLX Performance

11-02-2007, 07:50 AM

Phoronix: ATI Open vs. Closed AIGLX Performance

For those that may have missed it, the ATI/AMD fglrx 8.42 display driver that was released last month had introduced AIGLX support. The open-source "Radeon" driver for ATI graphics cards going up to the R400 generation has supported AIGLX for quite some time, but the ATI binary display driver hadn't until last month. However, one of the complaints about the fglrx implementation of AIGLX is that in the 8.42.3 driver, some are encountering slow performance in Compiz / Compiz Fusion. We have taken an ATI Radeon X800XL 256MB PCI-E graphics card, which is supported by both the Radeon and fglrx drivers, and have compared their Compiz performance in a few different scenarios.

Comment

Well, the the fglrx driver is fast when AIGLX is doing its job, but there are some areas like scrolling where the CPU usage with the fglrx driver is very high and you experience lag. Also, the AIGLX still has some bugs especially with Xserver 1.4 where it does not work at all. I think that these issues should be fixed by 8.43, or 8.44 at last so this is no real problem to me. It's not that I need Compiz.

Comment

Another article telling us how better fglrx drivers are...
Come on just take a quick look at the 8.42.3 forum topic here on phoronix EVERYONE is complaining about it being much slower on compiz with AIXGL than the older ones with XGL. Please Michael be fair I'm sure that you feel that too, just use it!!! I'm not blaming too much ATI for that, for sure they are doing hard work but thy are simply still not there. I cant' see any reason why articles on this site keep encourageing people to try the new driver when YOU know they are going to be disappointed!
Please tell the truth, "things are getting better let's give ati couple more months, but 8.42 is still just beta quality".

Not willing to flame, just a bit disappointed by phoronix, I love your site and I hate thinking you are not fair when talking about ATI.

Bye.
Diego

Comment

Another article telling us how better fglrx drivers are...
Come on just take a quick look at the 8.42.3 forum topic here on phoronix EVERYONE is complaining about it being much slower on compiz with AIXGL than the older ones with XGL. Please Michael be fair I'm sure that you feel that too, just use it!!! I'm not blaming too much ATI for that, for sure they are doing hard work but thy are simply still not there. I cant' see any reason why articles on this site keep encourageing people to try the new driver when YOU know they are going to be disappointed!
Please tell the truth, "things are getting better let's give ati couple more months, but 8.42 is still just beta quality".

Not willing to flame, just a bit disappointed by phoronix, I love your site and I hate thinking you are not fair when talking about ATI.

Bye.
Diego

I agree, the performance with the old driver and XGL is much better than the new one with AIGLX, unfortunately I don't have any benchmarks to back that statement up, but I can tell just by using it that xgL was much smoother. I know this new driver is beta and a whole new code base and they need some time. I just don't like that this whole topic is glossed over in the review.

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This tests for me doesn' count anything. The only thing it counts for me is that AIGLX + compiz + radeon9600 + fglx 8.42.3 make my system cry and I can't scroll anything without having my head destroyied into the monitor.

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For me the problem was not FPS but responsiveness. If I was actually rotating the cube in old+XGL vs new+AIGLX the rotation itself was smooth in both cases (probably more FPS in AIGLX, but whatever).

But when I hold down ctrl+alt and the left mouse button the old driver with XGL immediately and smoothly zooms out to reveal the cube. There is no hesitation or jerkiness, no matter what I'm doing. Doing the same thing on the new driver with AIGLX there is all sorts of hesitation, even though the actual cube navigation is smooth.

The exact same thing happened with wobbly windows. Once the window was moving around they were both very smooth. But _starting_ the move was something the old driver with XGL did beautifully and seamlessly. The new one took a moment before the jerkiness and tearing died down.

Now, this is on the exact same hardware with the same kernel and X version. (Ubuntu 7.10 for anyone interested). The new driver with Compiz is just not responsive enough. It probably pushes the polygons just fine, for whatever it's worth.

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I have the graphics card that this test was done with, and an AMD64 3000+. I've tried AIGLX with the versions of Beryl and Compiz that come with Feisty, and it doesn't usually seem to perform well enough (that is to say, I prefer Metacity over either one). For example, maximizing a window with wobble enabled just shows a couple of frames, because it has to wait for the backend (gnome-terminal, firefox) to redraw its contents, I think. Cube spinning works well, and all that, but when you actually start doing something, it usually starts lagging if the windows have some more elaborate content. I used to try Xgl, but that was with a Radeon 9600 Pro, so I can't compare. Thus, I'm not sure if I should blame Ati, either. Actually, I think I shouldn't, seeing that the new driver seems to give a big performance gain in general. Could it be that AIGLX support in fglrx is done badly, or that it can improve? Or is it just that Beryl and Compiz are cheap hacks?
No matter, I tend to use Xmonad anyway. But I do like to zoom in on Youtube videos using 'zoom' occasionally. Glad I can do it without Xgl now.